Pallasator pictured in winning action at Sandown© Photo Healy Racing
Pallasator is to join Gordon Elliott for a hurdling career.
A Group Two winner on the level for Sir Mark Prescott in 2015, the giant eight-year-old gelding's form this season has not been up to that level.
Pallasator, who is known to have a quirk or two, remains in the ownership of Qatar Racing Limited, who already have horses in training with Elliott.
He signed off for Prescott when eighth in the Doncaster Cup.
Prescott's assistant William Butler told Press Association Sport: "He's made us work, but we've had some great days with him.
"We'll be sad to see him go, but it was a sporting end to it at Doncaster with Rosie (Jessop) riding him, given how much work she's done with him.
"I hope it sparks him back to life and he's still got his enthusiasm as it takes a very good horse to work with him.
"He's been here nearly seven years and is very popular on the (Newmarket) Heath. People are fond of him."
